ARLINGTON, Texas — Six Flags' president says the amusement park company is using "both internal and external experts" to investigate the roller-coaster accident that killed a woman at its Dallas-area park.

Jim Reid-Anderson offered no details about the investigation during a conference call Monday to discuss the company's earnings. But he said the company was using experts from within and outside the company.

Reid-Anderson said Six Flags officials were joining the call with "heavy hearts."

Rosa Ayala-Goana was killed when she fell Friday from the Texas Giant roller coaster at Six Flags Over Texas in Arlington, a western suburb of Dallas.

Witnesses told authorities that Ayala-Goana expressed concern moments before the 14-story ride began that the safety bar had not completely engaged.